A liquid crystal display (LCD) device includes a plurality of circuit boards. Voltages of chip components of all the circuit boards are respectively reduced in accordance with voltages required by the chip components. FIG. 1 shows a typical LCD device control system, including a power circuit board, a scalar circuit board, and a control circuit board. Alternating current (AC) is converted by a flyback circuit of the power circuit board, to output 24V to supply power to a voltage converter, and output 12V to supply power to the scalar circuit board and the control circuit board. The scalar circuit board includes two voltage reduction modules, where one of the voltage reduction modules outputs 3.3V to the scalar circuit board. The control circuit board includes corresponding voltage reduction modules, where one of the voltage reduction modules further outputs the 3.3V to a sequence control circuit. The voltage reduction method results in repeated voltage reduction components, thereby causing component waste, and increasing energy consumption.